Worm-gear machinery



(No Model.)

S. OVERTON 8v HWELLS.

WORM GEAR MACHINERY.

Patented July 11 N. PETERS, Pbolo-Lilhognpmr. Wnhnn'lon. D. C.

' UNITED STATES PATENT OFFICE.

SAMUEL OVERTON AND EDWARD WELLS, OF CHICAGO, ILLINOIS.

WORM-GEAR-MACHINERY.

SPECIFICATION forming part of Letters Patent No. 260,892, dated July'll, 1882. f

Application filed August 13, 1881. (N0 model.)

To all whom it may concern Be it known that we, SAMUEL OVERTON and EDWARD WELLS, of Chicago, in the county of Cook and State of Illinois, have invented a new and valuable Improvement in Worm-Gear Machinery; and we do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being bad to the annexed drawing, making a part of this specification, and to the letters and figures of reference marked thereon.

The sole figure in the drawing represents a front elevation of our device.

The object of our invention is to provide-a suitable means of taking up lost motion in worm-wheel gearing, such as is generally used in elevator and hoisting machinery; and it consists in making the worm in two separate castingsor pieces,andprovidingsuitablemeans of adjustment, as hereinafter more fully described.

A in the drawing represents the worm-gear which rotates on axle b.

a a are bearings which support shaft B, on which the two tapering or conical worms 0 and d are fastened with set-screws e and f.

0 represents a pulley, which is intended to be driven by a belt.

In machinery of this kind where it is intended to reverse it is found that after the worm becomes much worn the shock is so great as to not only damage certain parts of the machinery, but in some cases (passenger elevators, for instance) becomes very disagreeable. To obviate this we make two separate worms, which are located a sufficient distance from each other to allow of adjustment as the teeth of the wheel and threads of the worms become worn so as to cause lost motion, or what istermed in toothed gearing backlash. We loosen one of the set-screws and. setup the worm by slightly turning or moving it toward the opposite worm until there is no lost motion between the teeth of wheel and the worms. The set-screw may then be tightened, and the machine will run smoothly. It will be seen that the adjustment may be made by setting up either or both of the worms,if itis desirable to do so; and to prevent slipping, the shaft B may be provided with screw-threads and jamnuts to follow behind each of the worms 0 and d. The hub of pulley C and the collarX are kept closely in contact with the bearings a a to prevent end motion of the shaft B.

Having thus described ourinvention, what we claim, and desire to secure by Letters'Patent, is-

The tapering worms 0 and d, made separate and attached to the same driving-shaft, and provided with suitable means of adjustment, in combination with the worm-gear A, substantially as shown, and for the purpose herein described.

In testimony that we claim the above we have hereunto subscribed our names in the presence of two witnesses.

SAMUEL ()VERTON. EDWARD WELLS.

Witnesses:

ISAAC J. FRANKLIN, IVIATHEW MURPHY. 

